20” barrel versus 16” barrel ..?

[Buncheong]

Did a search before posting; nothing came back on M4C. Found something on “another site” with info that did. not. scan. So to speak.

Question from a non-combat, Generation Iron Sites ex-USAF: am I gaining anything besides longer site radius and velocity with a 20” barrel, versus sticking with 16”?

As I save and plan for (new/upcoming) projects, my 20” ARs seem like more a sentimental favorite and/or luxury, rather than something conferring any advantage. I’m thinking 16” barrels and uppers are probably the way I ought to go.

Any input appreciated, all perspectives welcomed.

Thanking you in advance ...

[jsbhike]

Change in feel/handling for carry, aiming, and cycling.

Muzzle blast/flash should be less with 20".

Somewhat theoretical, but with a given barrel profile a 16" should be more accurate inside of X distance where the bullet is stabilized while the 20" extra velocity should translate to more accuracy beyond that point.

Most of that is really into splitting hairs territory.

[Wake27]

Rifle length gas will shoot softer too. But, as said above, all of this is very much splitting hairs. 20" guns are like 10.3" guns to me - very niche and while not bad, 16" and 11.5" (respectively) are probably a better GP fit. I would like an M16A4ish at some point, but that's entirely for collectorisms and would probably almost never get shot.

[Buncheong]

Change in feel/handling for carry, aiming, and cycling.

Muzzle blast/flash should be less with 20".

Somewhat theoretical, but with a given barrel profile a 16" should be more accurate inside of X distance where the bullet is stabilized while the 20" extra velocity should translate to more accuracy beyond that point.

Most of that is really into splitting hairs territory.

I sure appreciate the feedback, thanks much.

[Buncheong]

I would like an M16A4ish at some point, but that's entirely for collectorisms and would probably almost never get shot.

You’ve just described my situation pretty well.

Thanks much for the feedback, I sure appreciate it.

[3 AE]

Since you already have several 20" ARs, see if you can try out someone's 16" upper/carbine. Use the same ammo at the same distances, same sights/optics if possible, and same weather conditions and judge for yourself. It would probably make for an informative day of shooting.

[Slater]

Supposedly the 20 inch system puts a bit less stress on the internals.

[Clint]

16" barrels are lighter and handier than 20" barrels.

They're great for general purpose use and can run really nicely with a longer than MID length gas system.

[MontanaMarine]

You don't have to give up sight radius on a 16".

Here's a look at my 'Dissipator', 16", carbine gas system.

[AndyLate]

Reduced muzzle blast and modestly increased velocity compared to a 16" barrel are the reasons I liked my 20" upper.

My 20" barrel was replaced by an 18" tube (also rifle gas) because velocity and blast are very close between the two lengths.

Andy